Method for the manufacture of lenses



XR le rq'973 1.466.973 M. TAKANASHI METHOD FOR THE IANUFACTURE OF LENSES Fllqd June 25 1921 kn. L

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umrsn STATES PATENT OFFICE. m0 TLILIABEI, OI TOKYO, :aru. m m m muracruaa or m amauaaanamaaaim. Berta! 10.489488.

Toallaelmitnyconcem:

Be it known that I, Mrrsuo Tanaxasm, a sub of the Em ror of Japan, residing at o. 1.905 Shi ibuya,'Shihu a-mach a 'loyntama-gun, T o-fu, in the m ire 0 Japan, have inven certain new an useful Improvements in a Method for the Mannfacture of Lewes, of which the following isa *zcifiation. 10 is invention relates to a method of mannfacturing le I and the object of the invention is to uce lenses by a simple operation, there y greatly reducing the cost of manufacture. is. to this invention, with the mentioned object in view, lemes are manufactured by insert uired number of pieces into circular holes formed inapteofmetaloranyothercom valanrefractory material, and then has so ti ing same in a suitable furnace -to such an extent that the inserted glam pieces are.

- $5 a lens formed in each of the holes in the said plate according to' the method of this invention. I

In carrying out the invention into efl'ect,

a late 1 as shown in the drawing is used,

40 w ich is of suitable metal or any other com.

perativel refractory material. This late is provi ed with required number 0 circular holes 2, as shown in the drawings. In each of these circular holes 2, a piece of 45 solid glass to be shaped to'lens is inserted, it being prevented -from droppingl out Then the plate 1, with the pieces of g ass inserted into the circular holes 2, is put into a suitable furnace, and is heated therein to such so an extent that the inserted pieces of material glass are molten to a YlBOOllSOOlldltlOn the viscomty being such that the inserted pieces of glass are not liable to drop out from the has found holes 2 and thus the molten glass-will, in each hole, be shaped to lens 3 havin partial ispzericalsurfaces by the action-o its surtension, as shown in Figure 3. The

plate 1 is thenv removed from the furnace,

. friction Now, it is to be understood thatthe present invention is not applied to the manu factors of lens of large dimensions and is particularly applicable to the manufacture of small lens r microscope. The inventor by experiments that in the case of manufacture of lens having diameter of less than 12 mm. the molten glass does not sag in the hole in the plate, and that the lass amumes fairly the shape of a convex ens as shown in the drawing. The R of the lens varies with the diameter of the hole in the plate and the quantity of the blank.

The invention has gone mto commercial use and the inventor has e rienced no difliculties at any time in m convex lenses for microsco b the meth as herein described and c What I claim is:

1. A method for the manufacture of lens, consisting in inserti a piece of glam into a circular hole form in a late of refractory material, then heating e same to such an extent that said glass piece is molter. to a viscous condition and is shaped to a lens having artial herical surfaces by the action '0 its sur tension.

2. A method of manuflamhcture of lfensss, con; sistingininsertingap 'tyo pieceso material glam into a plurality of circular holes formed in a plate of comparatively refractory material, then heati the same to such an extent that the saidg pieces are molten to a viscous condition and are shaped to lenses each having partial spherical surfaces by the action of surface tension.

tune.

MITSUO TAKANASHI.

In testimony whereof I allix my signai r x e v... 

